Abstract: The invention relates to a polyethylene molding composition which has a multimodal molar mass distribution and is particularly suitable for producing protective coatings on steel pipes. The molding composition has a density at a temperature of 23° C. in the range from 0.94 to 0.95 g/cm3 and an MFI190/5 in the range from 1.2 to 2.1 dg/min. It comprises from 45 to 55% by weight of a low molecular weight ethylene homopolymer A, from 30 to 40% by weight of a high molecular weight copolymer B of ethylene and another olefin having from 4 to 8 carbon atoms and from 10 to 20% by weight of an ultra high molecular weight ethylene copolymer C.

Abstract: The invention relates to a polyethylene composition with multi-modal molecular mass distribution, which is particularly suitable for blow molding of small containers with a volume in the range of from 200 to 5000 cm3 (=ml). The composition has a density in the range of from 0.955 to 0.960 g/cm3 at 23° C. and an MFR190/5 in the range from 0.8 to 1.6 dg/min. It composition from 45 to 55% by weight of a low-molecular-mass ethylene homopolymer A, from 20 to 35% by weight of a high-molecular-mass copolymer B made from ethylene and from another 1-olefin having from 4 to 8 carbon atoms, and from 20 to 30% by weight of an ultrahigh-molecular-mass ethylene copolymer C.

Abstract: The invention relates to a method for producing a poly-1-olefin by polymerization of a 1-olefin of the formula R4C?CH2, in which R4 is hydrogen or an alkyl radical having from 1 to 10 carbon atoms, in suspension, in solution or in the gas the gas phase, at a temperature of from 20 to 200° C. and a pressure of from 0.5 to 50 bar, in the presence of a catalyst which consists of the product of the reaction of a magnesium alkoxide with a transition-metal compound (component a) and an organometallic compound (component b), whose component (a) has been produced by reacting a transitionmetal compound of titanium, zirconium, vanadium or chromium with a gelatinous dispersion of the magnesium alkoxide in an inert hydrocarbon.

Abstract: The invention relates to a polyethylene molding composition which has a multimodal molar mass distribution and is particularly suitable for producing protective coatings on steel pipes. The molding composition has a density at a temperature of 23° C. in the range from 0.94 to 0.95 g/cm3 and an MFI190/5 in the range from 1.2 to 2.1 dg/min. It comprises from 45 to 55% by weight of a low molecular weight ethylene homopolymer A, from 30 to 40% by weight of a high molecular weight copolymer B of ethylene and another olefin having from 4 to 8 carbon atoms and from 10 to 20% by weight of an ultra high molecular weight ethylene copolymer C.

Abstract: The invention relates to a modified Ziegler catalyst for preparing a poly-1-olefin in suspension, in solution or in the gas phase, which catalyst comprises the reaction product of a magnesium alkoxide (component a) with a transition metal compound (component b) and an organometallic compound (component c) together with an additional component (d) comprising a compound of the chemical formula M?Rx where M is an element of main group IV of the Periodic Table, R is halogen or an organic radical such as alkyl having from 1 to 10 carbon atoms, oxyalkyl having from 1 to 10 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms in the ring and, if desired, from 1 to 6 substituents R? on the ring, aryl having from 6 to 10 carbon atoms in the aromatic and, if desired, from 1 to 6 substituents R? on the aromatic, where R? is a halogen or an alkyl radical having from 1 to 4 carbon atoms or an OH group or an NO2 group or an oxyalkyl radical having from 1 to 4 carbon atoms, and x is an integer from 1 to 4.

Abstract: The invention relates to a polyethylene composition with multi-modal molecular mass distribution, which is particularly suitable for blow molding of small containers with a volume in the range of from 200 to 5000 cm3 (=ml). The composition has a density in the range of from 0.955 to 0.960 g/cm3 at 23° C. and an MFR190/5 in the range from 0.8 to 1.6 dg/min. It comprises from 45 to 55% by weight of a low-molecular-mass ethylene homopolymer A, from 20 to 35% by weight of a high-molecular-mass copolymer B made from ethylene and from another 1-olefin having from 4 to 8 carbon atoms, and from 20 to 30% by weight of an ultrahigh-molecular-mass ethylene copolymer C.

Abstract: The invention relates to a polyethylene composition with multimodal molecular mass distribution, which is particularly suitable for the blow molding of large containers with a volume in the range of from 10 to 150 dm3 (I). The composition has a density in the range of from 0.949 to 0.955 g/cm3 at 23° C. and an MFI190/5 in the range of from 0.1 to 0.3 dg/min. It comprises from 38 to 45% by weight of a low-molecular-mass ethylene homopolymer A, from 30 to 40% by weight of a high-molecular-mass copolymer B made from ethylene and from another 1-olefin having from 4 to 8 carbon atoms, and from 18 to 26% by weight of an ultrahigh-molecular-mass ethylene copolymer C.

Abstract: The invention relates to a polyethylene composition with multimodal molecular mass distribution, which is particularly suitable for the blow moulding of canisters having a volume in the range of from 2 to 20 dm3 (I). The composition has a density in the range from 0.950 to 0.958 g/cm3 at 23° C. and an MFR190/5 in the range of from 0.30 to 0.50 dg/min. It comprises from 40 to 50% by weight of a low-molecular-mass ethylene homopolymer A, from 25 to 35% by weight of a high-molecular-mass copolymer B made from ethylene and from another olefin having from 4 to 8 carbon atoms, and from 24 to 28% by weight of an ultrahigh-molecular-mass ethylene copolymer C.

Abstract: The invention relates to a polyethylene composition with multimodal molecular mass distribution, which is particularly suitable for the blow molding of L-ring drums having a volume in the range of from 50 to 250 dm3 (I). The composition has a density in the range of from 0.950 to 0.956 g/cm3 at 23° C. and a MFR1gp/21.6 in the range from 1.5 to 3.5 dg/min. It comprises from 35 to 45% by weight of a low-molecular-mass ethylene homopolymer A, from 34 to 44% by weight of a high-molecular-mass copolymer B made from ethylene and from another 1-olefin having from 4 to 8 carbon atoms, and from 18 to 26 % by weight of an ultrahigh-molecular-mass ethylene copolymer C.

Abstract: The invention relates to a method for producing a poly-1-olefin by polymerisation of a 1-olefin of the formula R4CH?CH2, in which R4 is hydrogen or an alkyl radical having from 1 to 10 carbon atoms, in suspension, in solution or in the gas phase, at a temperature of from 20 to 200° C. and a pressure of from 0.5 to 50 bar, in the presence of a catalyst which consists of the product of the reaction of a magnesium alkoxide with a transition-metal compound (component a) and an organometallic compound (component b), whose component a has been produced by reacting a transition-metal compound of titanium, zirconium, vanadium or chromium with a gelatinous dispersion of the magnesium alkoxide in an inert hydrocarbon.

Abstract: The invention relates to a modified Ziegler catalyst for preparing a poly-1-olefin in suspension, in solution or in the gas phase, which catalyst comprises the reaction product of a magnesium alkoxide (component a) with a transition metal compound (component b) and an organometallic compound (component c) together with an additional component (d) comprising a compound of the chemical formula M—Rx where M is an element of main group IV of the Periodic Table, R is halogen or an organic radical such as alkyl having from 1 to 10 carbon atoms, oxyalkyl having from 1 to 10 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms in the ring and, if desired, from 1 to 6 substituents R? on the ring, aryl having from 6 to 10 carbon atoms in the aromatic and, if desired, from 1 to 6 substituents R? on the aromatic, where R? is a halogen or an alkyl radical having from 1 to 4 carbon atoms or an OH group or an NO2 group or an oxyalkyl radical having from 1 to 4 carbon atoms, and x is an integer from 1 to 4.

Abstract: The invention relates to a method for producing a poly-1-olefin by polymerization of a 1-olefin of the formula R4C?CH2, in which R4 is hydrogen or an alkyl radical having from 1 to 10 carbon atoms, in suspension, in solution or in the gas phase, at a temperature of from 20 to 200° C. and a pressure of from 0.5 to 50 bar, in the presence of a catalyst which consists of the product of the reaction of a magnesium alkoxide with a transition-metal compound (component a) and an organometallic compound (component b), whose component (a) has been produced by reacting a transitionmetal compound of titanium, zirconium, vanadium or chromium with a gelatinous dispersion of the magnesium alkoxide in an inert hydrocarbon.

Abstract: A polyethylene molding material has a bimodal molecular weight distribution with an overall density of ≧0.948 g/cm3 and a melt flow index MFI190/5 of ≦0.2 dg/min. The molding material comprises from 35 to 65% by weight of low-molecular-weight ethylene hompolymer A having a viscosity number VNA in the range from 40 to 90 cm3/g, a melt flow index MFI190/2.16 A in the range from 40 to 2000 dg/min and a density dA of ≧0.965 g/cm3. Also included is from 35 to 65% by weight of high-molecular-weight ethylene copolymer B having a viscosity number VNB in the range from 500 to 2000 cm3/g, a melt flow index MFI190/5 B in the range from 0.02 to 0.2 dg/min and a density dB in the range from 0.922 to 0.944 g/cm3.

Abstract: The invention relates to a polyethylene moulding compound having a multimodal molecular weight distribution which has an overall density of ≧0.940 g/cm3 and an MFI190/5 in the range from 0.01 to 10 dg/min. The moulding compound according to the invention comprises an amount of from 30 to 60% by weight of low-molecular-weight ethylene homopolymer A which has a viscosity number VNA in the range from 40 to 150 cm3/g, an amount of from 30 to 65% by weight of high-molecular-weight copolymer B comprising ethylene and a further olefin having from 4 to 10 carbon atoms which has a viscosity number VNB in the range from 150 to 800 cm3/g, and an amount of from 1 to 30% by weight of ultrahigh-molecular-weight ethylene homopolymer C which has a viscosity number VNC in the range from 900 to 3000 cm3/g. The invention also relates to a method for the production of the moulding compound in a three-step process, and to the use thereof for the production of hollow articles.

Abstract: The novel process for preparing ethylene copolymers by polymerizing ethylene with, as comonomer, up to 10% by weight, based on the total amount of the monomers, of a 1-olefin of the formula R—CH═CH2, where R is a straight-chain or branched alkyl radical having from 1 to 4 carbon atoms, is carried out in a polymerization reactor and in suspension with a dispersion medium at a temperature of from 20 to 100° C. and a pressure of from 2 to 20 bar, in the presence of a catalyst. The dispersion medium is then separated from the polymer. After carrying out the polymerization, but before removing the dispersion medium from the polymer, the suspension stream is partly evaporated, with the result that some of the wax formed in the polymerization is adsorbed onto the polymer and the resultant vapor stream is fed directly into the reactors after condensation or back into the process after distillative removal of the comonomer.

Abstract: A catalyst formed by the reaction of a magnesium alkoxide dispersion having a particle size of from 100 to 3000 nm with a compound of a metal selected from the group comprising titanium, zirconium, vanadium and chromium and then with a chlorine-containing organoaluminum compound possesses a very good hydrogen responsiveness and a high activity even in the presence of molecular-weight regulators such as hydrogen. The catalyst is therefore outstandingly suitable for the production of low molecular-weight polyolefins. The catalyst makes possible the production of waxes having a reduced residual ash content. The large particle diameter and the low fines content of the polymer powder produced by suspension polymerization with this catalyst enables easy removal of the suspension medium and drying. The catalyst is furthermore advantageously used in solution polymerization and, because of the large particle diameter, in gas phase polymerization for producing low molecular-weight poly-1-olefins.

Abstract: The invention relates to a high strength pipe of ethylene polymer having a bimodal molecular weight distribution. Such pipe has a stress cracking resistance of .gtoreq.1400 h, a fracture toughness of .gtoreq.7 mJ/mm.sup.2 and a modulus of creep in flexure, measured according to DIN 54852-Z4, of .gtoreq.1100 N/mm.sup.2. The pipe according to the invention is produced from an ethylene polymer in which the ratio of weight of the low molecular weight fraction to the weight of the higher molecular weight fraction is in the range from 0.5 to 2.0 and which has a melt flow index MFI.sub.5/190.degree. C. of .ltoreq.0.35 g/10 min. It is particularly suitable for the transportation of gases and water.

Abstract: Process for preparing a poly-1-olefinBy means of a highly active spherical Ziegler catalyst based on a dialkylmagnesium, spherical polymers can be obtained in the polymerization of alpha-olefins. A further advantage of the catalyst of the invention lies in the high catalyst activity, so that only very small amounts of the catalyst are required for the polymerization. The residual titanium and/or zirconium content in the polymers prepared according to the invention is less than 10 ppm. Owing to its good responsiveness to hydrogen, the catalyst is particularly suited to two-stage processes for preparing polymers having a broad bimodal molecular weight distribution. The replacement of sulfur-containing electron donors such as diethyl sulfite by alcohols such as ethanol leads to less odor problems and broadened opportunities for use of the polymer.

Abstract: A process for the preparation of a polyolefin wax by polymerization or copolymerization of olefins or diolefins in suspension and in the presence of a catalyst. The process utilizes a metallocene and a cocatalyst, wherein the metallocene is a compound of the formula I ##STR1## in which M.sup.1 is a metal of group IVb, Vb or VIb of the Periodic Table of Elements, R.sup.1 and R.sup.2 are identical or different and are a hydrogen atom, a C.sub.1 -C.sub.10 -alkyl group, a C.sub.1 -C.sub.10 -alkoxy group, a C.sub.6 -C.sub.10 -aryl group, a C.sub.6 -C.sub.10 -aryloxy group, a C.sub.2 -C.sub.10 -alkenyl group, a C.sub.7 -C.sub.40 -arylalkyl group, a C.sub.7 -C.sub.40 -alkylaryl group, a C.sub.8 -C.sub.40 -arylalkenyl group or a halogen atom and R.sup.3 and R.sup.4 are identical or different and are a mononuclear or polynuclear hydrocarbon radical which may form a sandwich structure with the central atom M.sup.

Abstract: Organic substrate surfaces, particularly of industrial polymers, are provided by fluorination or chlorination with corresponding layers so as to obtain certain properties; for the purpose of improving the application of a layer, the surfaces are exposed beforehand at temperatures between 25.degree. C. and 300.degree. C. to hydrogen or a gas containing at least 0.1% by volume of hydrogen.